The overall aim of the total project has been the study of the sequential metabolic steps involved in the carcinogenesis by aromatic amines and amides. There has been unequivocal evidence that metabolic N- hydroxylation is the first step of activation in the carcinogenic process. Recent investigations from several laboratories including our own have demonstrated that enzymatic esterifications such as sulfurylation and phosphorylation of N-hydroxy amides might be the second step of activation in the carcinogenic process. Our recent non- enzymatic studies in vitro have shown acetylation of N-hydroxy amides by acetyl-CoA to form reactive esters and carbamylation of carcinogenic hydroxamic acids by carbamyl phosphate to form reactive esters. The overall aim of the total project has been the study of aromatic amides involving these activation steps.